#my_math.py
def add(a, b):
    return a + b

def subtract(a, b):
    return a - b

def multiply(a, b):
    return a * b

def divide(a, b):
    if b == 0:
        raise ValueError('除数不能为0')
    return a / b

print(__name__)
# print(f'测试{add(1, 2)}')
# print(f'测试{subtract(1, 2)}')
if __name__ == "__main__":
    print(f'测试{add(1, 2)}')
    print(f'测试{subtract(1, 2)}')
